As a first conventional heating cooker, there is a rice cooker in which a stirrer is rotatably provided on a lid that opens and closes an upper part of a rice cooker body, the stirrer being driven by a rotation driving unit to stir boiling objects or ingredients in an inner pot (see, e.g., JP 2008-278924 A (PTL1)).
The above rice cooker has the following problem. In cooking a mixture of water and cooking ingredients for Nikujaga (simmered meat and potatoes) or Chikuzen-ni (chicken and vegetables fried and boiled with soy), outer peripheral portions of the water surface in the inner pot rise during the stirring operation so that the cooking ingredients (onion, burdock etc.) tend to stick to a side surface (at positions higher than the water level) of the inner pot. Further, while a large amount of cooking ingredients contained in the inner pot is being stirred in one direction continuously, cooking ingredients stacked one on another tend to be pushed up against the inner side surface of the inner pot, thus being kept from being immersed in the broth. This causes heating nonuniformities and scorching.
As a second conventional heating cooker, there is a rice cooker having a stirring function for stirring rice and water in an inner pot (see, e.g., JP 2008-18112 A (PTL2)). With this rice cooker, water absorption time is shortened by stirring the rice and water in the container in a water absorption step during the rice cooking.
The above rice cooker has the following problem. In cooking foods using cooking ingredients which are increased in viscosity by being heated, such as jam, boiled beans, and Tsukudani of mushrooms (mushrooms boiled down in soy source) of mushrooms, air bubbles generated reach the lid, as a result of which the ingredients boil over. For this reason, this rice cooker is incapable of cooking foods, such as jam, that tend to boil over.